// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_WM_CORE_COMPOUND_EVENT_FILTER_H_
#define UI_WM_CORE_COMPOUND_EVENT_FILTER_H_

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/observer_list.h"
#include "ui/events/event.h"
#include "ui/events/event_handler.h"
#include "ui/gfx/native_widget_types.h"
#include "ui/wm/wm_export.h"

namespace aura {
class CursorManager;
class RootWindow;
}

namespace ui {
class GestureEvent;
class KeyEvent;
class LocatedEvent;
class MouseEvent;
class TouchEvent;
}

namespace wm {

// TODO(beng): This class should die. AddEventHandler() on the root Window
//             should be used instead.
// CompoundEventFilter gets all events first and can provide actions to those
// events. It implements global features such as click to activate a window and
// cursor change when moving mouse.
// Additional event filters can be added to CompoundEventFilter. Events will
// pass through those additional filters in their addition order and could be
// consumed by any of those filters. If an event is consumed by a filter, the
// rest of the filter(s) and CompoundEventFilter will not see the consumed
// event.
class WM_EXPORT CompoundEventFilter : public ui::EventHandler {
public:
    CompoundEventFilter();
    ~CompoundEventFilter() override;

    // Returns the cursor for the specified component.
    static gfx::NativeCursor CursorForWindowComponent(int window_component);

    // Adds/removes additional event filters. This does not take ownership of
    // the EventHandler.
    // NOTE: These handlers are deprecated. Use env::AddPreTargetEventHandler etc.
    // instead.
    void AddHandler(ui::EventHandler* filter);
    void RemoveHandler(ui::EventHandler* filter);

private:
    // Updates the cursor if the target provides a custom one, and provides
    // default resize cursors for window edges.
    void UpdateCursor(aura::Window* target, ui::MouseEvent* event);

    // Dispatches event to additional filters.
    void FilterKeyEvent(ui::KeyEvent* event);
    void FilterMouseEvent(ui::MouseEvent* event);
    void FilterTouchEvent(ui::TouchEvent* event);

    // Sets the visibility of the cursor if the event is not synthesized.
    void SetCursorVisibilityOnEvent(aura::Window* target,
        ui::Event* event,
        bool show);

    // Enables or disables mouse events if the event is not synthesized.
    void SetMouseEventsEnableStateOnEvent(aura::Window* target,
        ui::Event* event,
        bool enable);

    // Overridden from ui::EventHandler:
    void OnKeyEvent(ui::KeyEvent* event) override;
    void OnMouseEvent(ui::MouseEvent* event) override;
    void OnScrollEvent(ui::ScrollEvent* event) override;
    void OnTouchEvent(ui::TouchEvent* event) override;
    void OnGestureEvent(ui::GestureEvent* event) override;

    // Additional pre-target event handlers.
    base::ObserverList<ui::EventHandler, true> handlers_;

    DISALLOW_COPY_AND_ASSIGN(CompoundEventFilter);
};

} // namespace wm

#endif // UI_WM_CORE_COMPOUND_EVENT_FILTER_H_
